Anterior Transcorporeal Approach to Percutaneous Endoscopic Cervical Diskectomy for Single-Level Cervical Intervertebral Disk Herniation: Case Series with 2-Year Follow-Up

Evolution of Cervical Endoscopic Spine Surgery: Current Progress and Future Directions-A Narrative Review

Cervical endoscopic spine surgery is rapidly evolving and gaining popularity for the treatment of cervical radiculopathy and myelopathy. This approach significantly reduces muscular damage and blood loss by minimizing soft tissue stripping, leading to less postoperative pain and a faster postoperative recovery. As scientific evidence accumulates, the efficacy and safety of cervical endoscopic spine surgery are continually affirmed. Both anterior and posterior endoscopic approaches have surfaced as viable alternative treatments for various cervical spine pathologies. Newer techniques, such as endoscopic-assisted fusion, the anterior transcorporeal approach, and unilateral laminotomy for bilateral decompression, have been developed to enhance clinical outcomes and broaden surgical indications. Despite its advantages, this approach faces challenges, including a steep learning curve, increased radiation exposure for both surgeons and patients, and a relative limitation in addressing multi-level pathologies. However, the future of cervical endoscopic spine surgery is promising, with potential enhancements in clinical outcomes and safety on the horizon. This progress is fueled by integrating advanced imaging and navigation technologies, applying regional anesthesia for improved and facilitated postoperative recovery, and incorporating cutting-edge technologies, such as augmented reality. With these advancements, cervical endoscopic spine surgery is poised to broaden its scope in treating cervical spine pathologies while maintaining the benefits of minimized tissue damage and rapid recovery.

Surgical Essentials and 2-Year Follow-Up Results of Channel Repair in Endoscopic Transcorporeal Discectomy for Cervical Disc Herniation

OBJECTIVE

To evaluate long-term outcomes and surgical essentials of channel repair in endoscopic transcorporeal discectomy for cervical disc herniation.

METHODS

From October 2019 to March 2020, 24 patients with cervical disc herniation underwent channel repair after percutaneous full-endoscopic anterior transcorporeal cervical discectomy. Five interventions were performed at C3-C4, 11 were performed at C4-C5, and 8 were performed at C5-C6. Clinical outcomes were evaluated by Neck Disability Index, Japanese Orthopaedic Association, and visual analog scale scores. Radiologic changes were evaluated with intervertebral disc height and drilled vertebral height.

RESULTS

All procedures were completed with a mean operating time of 86.40 ± 8.19 minutes. Swollen neck was observed in 5 patients, which resolved within 2 hours. At the final follow-up, Neck Disability Index, Japanese Orthopaedic Association, and visual analog scale scores were improved significantly compared with preoperative assessments (P < 0.05); intervertebral disc height was decreased significantly (P < 0.05); and loss of drilled vertebral height was not significant (P > 0.05). All 24 bony channels disappeared by 3 months postoperatively. No other complications were observed.

CONCLUSIONS

Percutaneous full-endoscopic anterior transcorporeal cervical discectomy with channel repair offers a minimally invasive and effective treatment option for patients with cervical disc herniation. This technique demonstrates favorable clinical outcomes, including preservation of cervical spine mobility and minimal complications. Although there was a significant loss of intervertebral disc height, no vertebral collapse occurred. Strict adherence to surgical indications and precautions is crucial for successful outcomes. Further research and long-term studies are required to validate the efficacy and safety of this approach in a larger patient population.

Percutaneous Fully-endoscopic Anterior Transcorporeal Procedure for the Treatment of Isolated Ossification of the Posterior Longitudinal Ligament in the Cervical Spine: A Case Report

BACKGROUND

With the development of spinal endoscopic techniques, on the basis of our previous experience in treating various types of cervical disc herniation with this endoscopic technique, we took the lead in applying the percutaneous fully endoscopic anterior transcorporeal procedure to be utilized in the treatment of the isolated cervical ossification of the posterior longitudinal ligament (OPLL).

CASE PRESENTATION

A 66-year-old male patient who weighed 57 kg, with a height of 169 cm was admitted to the hospital on September 16, 2021 because of recurrent pain and numbness in the neck, shoulder, and right arm for 2 years, which as aggravated for the last 2 weeks. Two years ago, the patient developed neck and shoulder pain accompanied by right arm pain without obvious predisposing factors, and numbness in the first web space of the right hand. In the last 2 weeks, he had difficulty moving the right arm, but no pain or numbness in the contralateral arm. MRI and CT scans demonstrated that the ossified posterior longitudinal ligament of the cervical 5/6 vertebrae with spinal canal stenosis and seriously compressed the spinal cord patient was treated with a percutaneous fully endoscopic anterior transcorporeal procedure.

CONCLUSION

Our percutaneous fully endoscopic anterior transcorporeal procedure is a feasible, minimally invasive surgery for treating isolated ossification of the posterior longitudinal ligament in the cervical spine.

Anterior transcorporeal approach combined with posterior translaminar approach in percutaneous endoscopic cervical discectomy for two-segment cervical disc herniation treatment: a technical report and early follow-up

OBJECTIVE

Full endoscopic techniques are being gradually introduced from single-segment cervical disc herniation surgery to two-segment cervical disc herniation surgery. However, there is no suitable full endoscopic treatment for mixed-type two-segment cervical disc herniation (MTCDH) in which one segment herniates in front of the spinal cord and the other segment herniates behind the spinal cord. Therefore, we introduce a new full endoscopic technique by combining an anterior transcorporeal approach and a posterior translaminar approach. In addition, we provide a brief description of its safety, efficacy, feasibility, and surgical points.

METHODS

Thirty patients with MTCDH were given full endoscopic surgical treatment by a combined transcorporeal and transforaminal approach and were followed up for at least 12 months.

RESULTS

Clinical assessment scales showed that the patient's symptoms and pain were significantly reduced postoperatively. Imaging results showed bony repair of the surgically induced bone defect and the cervical Cobb angle was increased. No serious complications occurred.

CONCLUSION

This technique enables minimally invasive surgery to relieve the compression of the spinal cord by MTCDH. It avoids the fusion of the vertebral body for internal fixation, preserves the vertebral motion segments, avoids medical destruction of the cervical disc to the greatest extent possible, and expands the scope of adaptation of full endoscopic technology in cervical surgery.

Narrative Review of Uniportal Posterior Endoscopic Cervical Foraminotomy

Cervical radiculopathy is a common and disabling cervical condition characterized by symptoms including axial neck pain, radicular pain, weakness, and numbness in one or both arms. Common causes include herniated discs and foraminal stenosis, often accompanied by varying degrees of degenerative disc disease and uncovertebral joint hypertrophy. In the treatment of cervical radiculopathy, there is an increasing preference for posterior foraminotomy over anterior cervical discectomy and fusion due to the avoidance of fusion-related complications. As endoscopic spine surgery techniques continue to evolve, there is a rising interest in posterior endoscopic cervical foraminotomy and posterior endoscopic cervical discectomy as effective treatments for cervical radiculopathy. Because these procedures can performed through a single subcentimeter incision with minimal soft tissue damage, they can often be carried out as ambulatory procedures. In this narrative review, we examined current literature addressing the indications, surgical techniques, outcomes, and potential complications associated with posterior cervical endoscopic approaches.

Complications of Cervical Endoscopic Spinal Surgery: A Systematic Review and Narrative Analysis

BACKGROUND

There are no systematic evidence-based medical data on the complications of endoscopic cervical spinal surgery. This narrative analysis compiled data from various studies that examined endoscopic complications, such as cervical disc herniation and foraminal stenosis. This study aimed to investigate the efficacy and safety of endoscopic surgery in cervical radiculopathy.

METHODS

We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and keywords were set as "endoscopic cervical spinal surgery", "endoscopic cervical discectomy", "endoscopic cervical foraminotomy", and "percutaneous endoscopic cervical discectomy". We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic cervical surgery was divided into three categories: full endoscopic anterior, endoscopic posterior, and unilateral biportal approaches. We excluded duplicate publications, studies without full text, studies without complications or incomplete information, and studies that did not provide the necessary data for extraction, animal experiments, or reviews.

RESULTS

Difficulties in swallowing, hematoma, and hoarseness are common complications associated with the anterior cervical approach. In contrast, complications of the posterior approach include nerve root injury, hematoma, and dysesthesia. However, endoscopic cervical spinal surgery, including the full endoscopic anterior, posterior, and unilateral biportal approaches, is a safe and effective treatment for cervical radiculopathy.

CONCLUSIONS

Complications of full endoscopic cervical spinal surgery differ significantly depending on the anterior and posterior approaches. In the anterior approach, swallowing difficulty, recurrent disc, hematoma, and dysphonia are the common complications. In contrast, transient dysesthesia, dural tears, upper limb motor deficits, and persistent arm pain are commonly reported with the posterior approach.

Surgeon reported practice patterns related to full endoscopic cervical decompression procedures

BACKGROUND

The microsurgical anterior approach to the cervical spine is commonplace. Fewer surgeons perform posterior cervical microsurgical procedures on a routine basis for lack of indication, more bleeding, persistent postoperative neck pain, and risk of progressive misalignment. In comparison, the endoscopic technique is preferentially performed through the posterior approach. Many spine surgeons and even surgeons versed in lumbar endoscopy are often reluctant to consider endoscopic procedures in the cervical spine. We report the results of a surgeon survey to find out why.

METHODS

A questionnaire of 10 questions was sent to spine surgeons by email and chat groups in social media networks including Facebook, WeChat, WhatsApp, and LinkedIn to collect practice pattern data about microscopic and endoscopic spine surgery in the lumbar and cervical spine. The responses were cross-tabulated by surgeons' demographic data. Pearson Chi-Square measures, Kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using the statistical package SPSS Version 27.0.

RESULTS

The survey response rate was 39.7%, with 50 of the 126 surgeons who started the survey submitting a completed questionnaire. Of the 50 surgeons, 56.2% were orthopedic, and 42% neurological surgeons. Most surgeons worked in private practice (42%). Another 26% were university-employed, 18% were in private practice affiliated with a university, and the remaining 14% were hospital employed. The majority of surgeons (55.1%) were autodidacts. The largest responding surgeon groups were between 35-44 years (38%) and between 45-54 years of age (34%). Half of the responding surgeons were routinely performing endoscopic cervical spine surgery. The other half did not perform it for the main hurdle of fear of complications (50%). Lack of appropriate mentorship was listed as second most reason (25.4%). More concerns for not performing cervical endoscopic approaches were the perception of lack of technology (20.8%) and suitable surgical indication (12.5%). Only 4.2% considered cervical endoscopy too risky. Nearly a third (30.6%) of the spine surgeons treated over 80% of their cervical spine patients with endoscopic surgeries. Most commonly performed were posterior endoscopic cervical discectomy (PECD; 52%), posterior endoscopic cervical foraminotomy (PECF; 48%), anterior endoscopic cervical discectomy (AECD; 32%), cervical endoscopic unilateral laminotomy for bilateral decompression (CE-ULBD; 30%), respectively.

CONCLUSION

Cervical endoscopic spine surgery is gaining traction among spine surgeons. However, by far most surgeons performing cervical endoscopic spine surgery work in private practice and are autodidacts. This lack of a teacher to shorten the learning curve as well as fear of complications are two of the major impediments to the successful implementation of cervical endoscopic procedures.

Complications and Management of Endoscopic Spinal Surgery

In the past, the use of endoscopic spine surgery was limited to intervertebral discectomy; however, it has recently become possible to treat various spinal degenerative diseases, such as spinal stenosis and foraminal stenosis, and the treatment range has also expanded from the lumbar spine to the cervical and thoracic regions. However, as endoscopic spine surgery develops and its indications widen, more diverse and advanced surgical techniques are being introduced, and the complications of endoscopic spine surgery are also increasing accordingly. We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and key words were set as “endoscopic spinal surgery,” “endoscopic cervical foramoinotomy,” “PECD,” “percutaneous transforaminal discectomy,” “percutaneous endoscopic interlaminar discectomy,” “PELD,” “PETD,” “PEID,” “YESS” and “TESSYS.” We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic lumbar surgery was divided into full endoscopic interlaminar and transforaminal approaches and a unilateral biportal approach. We performed a comprehensive review of available literature on complications of endoscopic spinal surgery. This study particularly focused on the prevention of complications. Regardless of the surgical methods, the most common complications related to endoscopic spinal surgery include dural tears and perioperative hematoma. transient dysesthesia, nerve root injury and recurrence. However, Endoscopic spinal surgery, including full endoscopic transforaminal and interlaminar and unilateral biportal approaches, is a safe and effective a treatment for lumbar as well as cervical and thoracic spinal diseases such as disc herniation, lumbar spinal stenosis, foraminal stenosis and recurrent disc herniation.

Outcome of Anterior and Posterior Endoscopic Procedures for Cervical Radiculopathy Due to Degenerative Disk Disease: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVES

Cervical spine endoscopic discectomy and decompression have gained popularity in the last decade. This review aimed to shed light on the current outcomes of cervical spine endoscopic procedures for degenerative disc disease (DDD) and to calculate a pooled estimate of various outcome measures.

METHODS

We retrieved articles published in English related to endoscopic cervical spine procedures from 3 central databases from inception until September 2020. A subgroup analysis based on the anterior versus the posterior approach was performed.

RESULTS

Thirty-one articles fulfilled the eligibility criteria and included 1,410 patients. A successful outcome was observed in 91.3% (88.6-93.4%, P = 0.000). This percentage was lower for the anterior approach (89.6% [85.8-92.5%], P = 0.000) than for the posterior approach (94.2% [90.4-96.5%], P = 0.000). A higher percentage of poor outcomes was reported for the anterior approach (5.7% [3.2-10.1%], P = 0.000 vs. 2.3% [1-5.5%], P = 0.000 for the posterior approach). The overall complication rate was 7.2% (5.2-9.8%, P = 0.000). There was a slightly higher complication rate for the anterior approach (7.9% [4.5-13.3%], P = 0.000) than for the posterior approach (6.7% [4.4-10%], P = 0.000). The revision rate was 4.2% (2.6-6.8%, P = 0.000); and 4.2% (1.8-9.7%, P = 0.000) for the anterior approach and 4.00% (2.2-7.4%, P = 0.000) for the posterior approach.

CONCLUSIONS

There is a higher success rate and lower complication rate with the posterior approach than with the anterior approach. However, high-quality randomized controlled trials are vital to evaluate the efficacy of these procedures.

[Posterior percutaneous endoscopy via vertical anchor technique combined with trench technique for single-segmental central cervical disc herniation]

Objective

To investigate the clinical feasibility, safety, and effectiveness of posterior percutaneous endoscopy via vertical anchor technique combined with trench technique for single-segmental central cervical disc herniation.

Methods

Between July 2017 and August 2019, 13 patients with the single-segmental central cervical disc herniation suffering from various neurologic deficits were treated with posterior percutaneous endoscopy via vertical anchor technique combined with trench technique. There were 6 males and 7 females with an average age of 50.5 years (range, 43-64 years). Disease duration ranged from 3 to 17 months (mean, 9.2 months). The clinical symptoms of 5 cases were mainly neck pain, radiculopathy, and numbness in upper limbs, and the visual analogue scale (VAS) score was 6.60±0.55. The clinical symptoms of 8 cases were myelopathy including upper extremities numbness, weakness, and trouble walking, and the modified Japanese Orthopedic Association (mJOA) score was 12.75±0.71. The surgery-related complications, operation time, and intraoperative blood loss were recorded, and the results of clinical symptoms were measured by VAS scores and mJOA scores.

Results

All procedures were completed successfully, no severe complications such as dural tears or cerebrospinal fluid leakage occurred. The operation time ranged from 83 to 164 minutes (mean, 101.2 minutes). The intraoperative blood loss was 25-50 mL (mean, 33.1 mL). After operation, 12 of 13 cases were followed up 10-24 months (mean, 17.6 months). The VAS scores of patients with preoperative pain symptoms were 2.40±0.55 on the first day after operation and 1.80±0.45 at last follow-up, which were significantly lower than those before operation ( P<0.05). The mJOA scores of patients with the symptoms of spinal cord injury were 12.63±0.52 on the first day after operation and 14.29±0.95 at last follow-up, and the score at last follow-up was significantly higher than that before operation ( P<0.05). Acute extremities weakness occurred for the postoperative hematoma formation in 1 case (disc herniation at C _{4, 5}) presented with myelopathy preoperatively, and muscle strength was recovered after the clearance of hematoma and spinal cord decompression under percutaneous endoscopy.

Conclusion

Posterior percutaneous endoscopy via vertical anchor technique and trench technique for single-segmental central cervical disc herniation was clinical feasible, safe, and effective, and could be an alternative approach to the treatment of central cervical disc herniation.

The Current State of Cervical Endoscopic Spine Surgery: an Updated Literature Review and Technical Considerations

Introduction: Endoscopic spine surgery has become one of the representative minimally invasive spine surgeries (MISS), especially in the lumbar spine. Full-endoscopic procedures using a working channel endoscope for cervical degenerative spine disease have been reported as practical and feasible. This review aimed to summarize the updated techniques of and studies about cervical endoscopic surgery. Areas covered: An extensive search of PubMed was performed for randomized controlled trials (RCTs) or comparative cohort studies on the full-endoscopic cervical procedure. All the 236 articles found were screened and categorized. Only two RCTs and four cohort studies finally met the search criteria. Regarding the surgical techniques, there are four categories according to the approach method: 1) anterior endoscopic cervical discectomy (AECD); 2) anterior endoscopic cervical transcorporeal decompression (AECTcD); 3) posterior endoscopic cervical foraminotomy and discectomy (PECFD); and 4) posterior endoscopic cervical laminotomy (PECL). Expert opinion: Cervical endoscopic surgery provides comparable clinical results with MISS benefits, such as shorter operative time, less bleeding, and earlier recovery time. However, spine surgeons are not yet familiar with most of these techniques; moreover, supportive evidence is minimal. Technical evolution is still ongoing in an effort to make the procedure more practical.

Parametric study of anterior percutaneous endoscopic cervical discectomy (APECD)

Anterior percutaneous endoscopic cervical discectomy (APECD) is a common treatment for cervical spondylotic radiculopathy (CSR). In this study, the effects of various channel diameters and approach angles on cervical vertebrae on postoperative outcomes in APECD surgery were explored. A finite element model of intact cervical C₃-C₇ was constructed and then modified to obtain six surgical models. Range of motion (ROM) and intradiscal pressure (IDP) were calculated under different conditions of flexion (Fle), extension (Ext), lateral bending, and axial rotation. During Fle and bending to the left (LB), the ROM was closer to the intact model when the angle of approach was 90°. During bending to the left (LB) and rotation to the left (LR), the ROM changed considerably (43.2%, 33.7%, respectively) where the angle of approach was 45°. As the surgical channel diameter increased, the extent of the change in ROM compared with the intact model also increased. IDP decreased by 48% and 49%, respectively, compared with the intact model at the C₅-C₆ segment where the angle of approach was 45° and 60° during Fle, while it changed little at 90°, by less than 10%. The IDP was increased noticeably by 117.6%, 82.1%, and 105.8%, for channel diameters of 2, 3 and 4 mm, respectively. And declined noticeably during LB and LR (LB: 27.1%, 27.1%, 38.5%; LR: 37.4%, 35.5%, 48.7%). The results demonstrated that the shorter the surgical path, the smaller surgical diameter, the less the biomechanical influence on the cervical vertebra.

Current and Future of Endoscopic Spine Surgery: What are the Common Procedures we Have Now and What Lies Ahead?

The aging population around the world leads to increasing incidence of degenerative spinal conditions. There is a need for a minimally invasive technique in treatment for spinal conditions to meet the medical complexity and comorbidities that comes with aging. Principles of endoscopy are similar to minimally invasive surgery, which is to decrease pressure on soft tissue crushing from prolonged retraction, avoid soft tissue stripping and dissection, and bone and ligamentous preservation for optimal decompression without excessive destruction. Endoscopic spine surgery techniques started slowly in development in the 1970s to 2000s, with a rapid phase of development since the turn of the 21st century with endoscopic solutions developing in cervical, thoracic, and lumbar conditions with increasing complexity in nature of operation. Technological enhancement with progressively supportive literature is pushing boundaries of endoscopy from the early days of soft tissue procedure to current fusion procedures, endoscopic spine surgery techniques is covering more areas of spine than ever previously possible with good clinical results. We present a review on the current techniques available and postulated near future development for endoscopic spine surgery.

Transcorporeal Tunnel Approach for Cervical Radiculopathy and Myelopathy: A Systematic Review and Meta-Analysis

OBJECTIVE

The transcorporeal tunnel approach is a relatively new alternative of anterior cervical decompression and fusion for the treatment of cervical radiculopathy and myelopathy, with its main presumed advantage being the preservation of the intervertebral space. The aim of the present article is to present the outcomes of the systematic review and meta-analysis regarding the short-term outcomes of this surgical technique.

METHODS

A systematic review and a meta-analysis using the random-effects method of the available studies were performed to assess the safety and efficiency of the transcorporeal tunnel approach for cervical radiculopathy and myelopathy.

RESULTS

In total, 15 eligible studies were identified, with a cumulative number of 254 patients. Pooled data yielded a complication rate of 0.053 and a failure rate of the technique of 0.081; a patient-reported favorable outcome of 0.94 was documented. The available data did not allow for a definite conclusion on the effects of the technique on the intervertebral space height.

CONCLUSIONS

Although technically challenging, like all minimally invasive methods, the transcorporeal tunnel approach seems to be a safe and efficient option for the treatment of cervical radiculopathy and myelopathy, presenting comparable outcome profiles to alternative open or less invasive techniques.